CASE REPORT Case Report: What—or who—killed Frank Ramsey? Some reflections on cause of death and the nature of medical reasoning [version 1; peer review: awaiting peer review] Cheryl Misak 1 , C David Naylor 1 , Mark Tonelli 2 , Trisha Greenhalgh 3 , Graham Foster 4 1 University of Toronto, Toronto, Canada 2 University of Washington, Seattle, Seattle, USA 3 University of Oxford, Oxford, UK 4 Queen Mary, University of London, London, UK First published: 23 May 2022, 7:158 https://doi.org/10.12688/wellcomeopenres.17759.1 Latest published: 23 May 2022, 7:158 https://doi.org/10.12688/wellcomeopenres.17759.1 v1 Abstract Philosopher Frank Ramsey died in 1930 aged only 26. There has been much speculation about the nature of his final illness and the sequence of events which led to his death. To prepare this case report, we traced Ramsey’s medical records and combined them with an extensive and unique dataset of contemporaneous sources. We use these to evaluate three possible explanations for Ramsey’s illness and its unexpectedly fatal trajectory—infectious (Weil’s disease), autoimmune (primary sclerosing cholangitis) and obstructive (gallstones). We explore how uncertainty surrounding each of these possibilities might have influenced Ramsey’s doctors’ thoughts and actions, including their ill-fated decision to perform the emergency operation that appears to have precipitated his final decline. We then reflect on the unfinished opus on which Ramsey was working when he died—on the nature of truth and how humans reason under conditions of uncertainty. We end with some thoughts linking Ramsey’s death to his philosophy. Keywords Weil's disease, gallstones, primary sclerosing cholangitis, uncertainty, Frank Ramsey Open Peer Review Approval Status AWAITING PEER REVIEW Any reports and responses or comments on the article can be found at the end of the article. Page 1 of 11 Wellcome Open Research 2022, 7:158 Last updated: 23 MAY 2022